Substituted,2,4-dioxodecahydroquinazolines



United States Patent 1,670,298 Int. Cl. C07d 51/48 US. Cl. 260-260 3 Claims ABSTRACT OF THE DISCLOSURE New and valuable substituted 2,4-di-oxodecahydroquinazolines and their use for controlling unwanted plants, and having the formula II o where R denotes an alkyl radical having from two trfour carbon atoms and A denotes the radical where R denotes'a linear or branched alkylene or alkylene group, a cycloalkylene group or an arylene group which may bear halogen atoms or nitro, alkyl or alkoxy groups as substituents, R denotes an alkyl, cycloalkyl or aryl radical and n denotes Zero or 1.

The present invention relates to new and valuable 2,4- dioxo-decahydroquinazoline derivatives and herbicides containing the same..

It is known that 3-isopropyl-2,4-dioxodecahydroquinazoline can be used as a herbicide (British patent specification No. 1,035,093). Its effects are however not satisfactory.

It is an object of the present invention to provide new and valuable substituted 2,'4-dioxodecahydroquinazolines. Another object of the invention is to provide new and valuable substituted 1-carbonyl-3-alkyl-2,4-dioxodecahydroquinazolines having good herbicidal properties. A further object of the invention is a method of controlling unwanted plants with the said active ingredients.

These and other objects and advantages of the invention are achieved by 2,4-dioxodecahydroquinazolines hav- Where R denotes an alkyl radical having from two to four carbon atoms and A denotes the radical -CO-(R COOR where R denotes a linear or branched alkylene or alkenylene group, a cycloalkylene group or an arylene group which may bear halogen atoms or nitro, alkyl or alkoxy groups as substituents, R denotes an alkyl, cyclo- 3,503,978 Patented Mar. 31, 1970 alkyl or aryl radical and n denotes zero or 1, having a very good herbicidal action.

The following are examples of alkylene radicals: methylene, ethylene, propylene, butylene, dimethylmethylene, l-propen-2-yl-ethylene and 1(2'methylpropen-2'- ylethylene) radicals.

Examples of alkylene radicals are: ethenylene, propenylene and butenylene radicals.

Examples of cycloalkylene radicals are: cyclopentylene, cyclohexylene and cyclododecylene radicals.

Examples of arylene radicals are: phenylene, toluylene, 2-chlorophenylene and 2,6-dichlorophenylene radicals.

Examples of alkyl groups are: methyl, ethyl, propyl, butyl and isobutyl groups.

Examples of cycloalkyl groups are: the cyclohexyl, cyclopentyl and cyclooctyl radicals.

An example of an aryl radical is phenyl which may bear halogen atoms or methyl or nitro groups as substituents.

The compounds according to this invention are particularly selective against broadleaved and grassy weeds in Indian corn and potato crops. The rate of application required is from 0.5 to 2 kilograms per hectare. Application may be before or after emergence of the crop plants.

The following are examples of active ingredients in accordance with this invention:

l-( a-carbomethoxy-a,a-dimethylacetyl) -3 -isopropyl-2,4-

dioxodecahydroquinazoline;

1- (a-propen-Z-yl-B-carboethoxypropionyl -3 -isopropyl- 2,4-dioxodecahydroquinazoline;

1-( a- (2-'methylpropen-2-yl 8-carboethoxypropionyl) 3-isopropyl-2,4-dioxodecahydroquinazoline;

1- (B-carboisobutyloxyacryloyl) -3-isopropyl-2,4-dioxodecahydroquinazoline;

1-(2-carboethoxybenzoyl) -3-isopropyl-2,4-dioxodecahydroquinazoline;

1-( ot-carbomethoxy-a,a-dimethylacetyl) -3 -isobutyl-2,4-

dioxodecahydroquinazoline;

1- (a-propen-2'-yl-,B-carboethoxypropionyl) -3-isobuty1- 2,4-dioxodecahydroquinazoline;

1-( a-methylpropen-2-yl -/8-carboethoxypropionyl) 3-isobutyl-2,4-dioxodecahydroquinazoline;

1- fl-c arb oisobutyloxyacryloyl) -3 -isobutyl-2,4-diox0- decahydroquinazoline; and

1- 2-carboethoxybenzoyl) -3 -isobutyl-2,4-dioxohydroquinazoline.

The active ingredients according to the invention are new. They may be synthesized according to the following equation by acylation of a 3-alkyl-2,4-dioxodecahydroquinazoline with a hemiester chloride of a dicarboxylic acid in the presence of a HCl acceptor.

where R, R, R and n have the meanings given above.

3 Since all compounds to be used according to the invention can be prepared by the same method, only the production of 1-(tx-carbomethoxy-a,a-dimethylacetyl)-3-isopropyl-2,4-dioxdecahydroquinazoline will now be described in detail.

hydrochloride deposited is suction filtered. The filtrate is washed with water until neutral, dried with anhydrous sodium sulfate and concentrated in a water-jet vacuum.

30 parts of a yellowish oil remains. Analysis.-Calcd. for C I-1 N 0 (338.42) (percent):

21 parts by weight of 3-isopropyl-2,4-dioxodecahydro- 5 3 Found (percent) 604; quinazoline and 12.2 parts by weight of triethylamine are i infr trum onfirm th Str cm of the dissolved in 300 parts by weight of toluene. While the compound a e spec c i s e u re reajmon vessel 18 bemg cooled wlth 18 parts The new active ingredients are mostly viscous oils h the n y e qhlorlde of dlmethylmalonlc which can only be distilled in a high vacuum with partial aCld 1S PP 111w thls solutlon at tempefaturfi of 0m decomposition. Their structure is verified by analysis and 10 to C. To complete the reaction, the mixt re is infrared spectra. Some of the newactive ingredients are further stirred for four hours at C. The triethylamine enumerated in the following table:

NR 1 H l /C=O 1T1 C0(R1 n COOR2 R CO( l)n COOR2 77.

CH: 000OO0H CHI'IQON205 (296.32) Gale; 0, 56.8;

CH- I-I,6.77; N,9.45. Found: 0, 56.7; 0H3 H, 6.7; N, 9.3.

C H3 1 CnHzeHzOs (338.42) (I; 0.10. 60.4;

CH- C0 0O00H H,7.75;N,8.25.

] Found: 0, 0.6; CH3 CH3 H,7.8; N, 8.1.

CH -C OCHCH2CH=CH2 1 CzoHauNzOs (378.46) Cale; C, 63.7;

CH- CHz-C 0 0 CzHfi H, 7.83; N, 7.4.

Found 0, 63.5; OH; H, 7.8; N, 7.3.

CH; H: 1 CnHazNzOs (392.49)

l 0.: 0,6 4.2; CH- COCHCHzC=CH2 H, 8.23; N, 7.13.

Found: 0,6 4.4. 0H GET-00002 H, 8.1; N, 7.0.

CH C 3 -COCH 1 CmH2sN2O (364.43) Cale; 62.7;

CH CH-CHz-O-CO-CH H, 7.66; N, 7.76. Found: 0,62.6; CH3 CH3 H, 7.7; N, 7.5.

CH; 1 C21H2 1N205 (386.44) -0O 02.10.: 0,654;

CH H, 6.74; N, 7.25.

Found: 0,65.3; CH CaH O--C O H, 6.6; N, 7.4.

CH CH7 1 ClaH2aNzO (352.44) I 0alc.: o, 61.4;

CHCHz- -COCCOOCH H,7.95; N,7.94 Found: 0, 61.5; CH CH3 H, 7.8; N, 7.8

CH3 C OCH3CH=CH3 1 C21H32N205 (392.49) c.: O, 64.2;

CHCHz CHgC0-O C2H H,8.23; N, .13.

Found: C, 4.1; C O; H, 8.4; N, 7.0.

CH3 CH3 1 C22H34Nz05 (406.51) l Cale: 0,652;

CH-CH2 -,COOHCH C=CH H, 8.44; N, 6.93.

Found: 0, 65.0; CH; CHz-C 0-0 02115 H, 8.5; N,6 s

CH CH -COCH C20HaoNzOs (378 46) ll Cale 0,615.5; CH-CHz- CH-OHg-O-CO-CH H, 7.94; N, 7.41

Found: 0,633.0; CH3 CH3 11,7.8; ,7.5

CH C21H2BN2O5 (460.46) CO-- 08.10.: C, 65.6;

CH-CHr- ,7.25; N, 6.99.

Found: 0, 5.5; CH CzH5O-CO H, 7.2; N,7.1.

The form of application of the agents according to the invention are used depends entirely on the purpose for which they are being used. In any case it should ensure a fine distribution of the active ingredient. They may be applied as solutions, emulsions, suspensions or dusts.

A solution in water is suitable for the production of solutions capable of direct spraying. Hydrocarbons such as tetrahydronaphthalene and alkylated naphthalenes may however also be used as vehicles for spraying.

Aqueous formulations may be prepared from emulsion concentrates, pastes or wettable powders by adding water. To prepare emulsions, the ingredients as such or dissolved in a solvent may be homogenized in water or an organic solvent by means of a wetting or dispersing agent. It is however also possible to prepare concentrates consisting of active ingredient, emulsifying or dispersing agent and possibly solvent; these concentrates are suitable for dilution with water. Dusts can be prepared by mixing or grinding the active ingredient with a solid carrier, for example diatomaceous earth, infusorial earth, clay or fertilizer.

Mixing with other herbicides is also possible and also the common application with fertilizers.

The following examples explain the eifect of the new compounds.

EXAMPLE 1 EXAMPLE 2 The plants Indian corn (Zea mays), white goosefoot (Chenopodium album), wild mustard (Sinapis arvensis), small nettle (Urtica urens), chickweed (Stellarz'a media), annual rye grass (Poa annua), slender foxtail (Al pecurus myosuroia'es) and barnyard grass (Echinochloa crusgalli) are treated at a growth height of 3 to 12 cm. with 1 (a carbomethoxy-a,a-dimethylacety1-3-isopropyl-2,4- dioxodecahydroquinazoline (I) and with the known potassium salt of 2-methy l-4-chlorophenoxy acetic acid (II for comparison, each at the rate of 1.5 kg. of active ingredient dispersed in or dissolved in 500 liters of Water per hectare.

Three to four weeks later the results shown in the following table are obtained:

Active ingredient 0. 30. 90 to 1000" 93 to 100.

Barnyard grass- 100=Total destruction.

0=No damage.

The herbicidal ingredients according to this invention may also be used as total herbicides by using higher rates of application.

The substances listed below (ddh=dioxodecahydroquinazoline) have the same effect as (I) in Examples 1 and 2:

1- a-propen-2'-yl-fl-carboethoxypropionyl) -3 -isopropyl- 2,4-ddh 1- oc- 2'-methylpropen-2-yl -/3-carboethoxypropionyl 3-isopropyl-2,4-ddh l- 8-carboisobutyloxyacryloyl) -3 -isopropyl-2,4-ddh 1-(2-carboethoxybenzoyl)-3-isopropyl-2,4-ddh 1- a-carbomethoxy-a,a-dimethylacetyl) -3-isobutyl-2,4-

ddh 1- a-propen-2'-yl-[i-carb oethoxypropionyl) -3-isobutyl- 2,4-ddh 1- oc- 2'-methylpropen-2-yl) -B-carboethoxypropionyl) -3- isobutyl-2,4-ddh 1-(B-carboisobutylacryloyl)-3-isobutyl-2,4-ddh 1-(2-carboethoxybenzoyl)-3-isobutyl-2,4-ddh and 1-carbomethoxycarbonyl-3-isopropyl-2,4-dioxodecahydroquinazoline. We claim: 1. A 2,4 dioxodecahydroquinazoline having the formula Where R denotes an alkyl radical of two to four carbon atoms and A denotes the radical CO(R COOR where R denotes methylene, ethylene, propylene, butylene, dimethylmethylene, 1-propen-2-yl-ethylene, 1-(2' methylpropen-2-ylethylene), ethnylene, propenylene, butenylene phenylene, toluylene, 2-chlorophenylene, and 2,6-dichlorophenylene, R denotes methyl, ethyl, propyl, butyl and isobutyl, and n denotes zero or 1.

2. l (a propen-2-yl-/3-carboethoxypropionyl)-3-isopropyl-2,4-dioxodecahydroquinazoline.

3. 1 (a carbomethoxy-a,a-dimethylacetyl)-3-isopropyl-2,4-dioxodecahydroquinazoline.

References Cited UNITED STATES PATENTS 3,235,363 2/1966 Luckenbaugh et a1. 260-260 ALEX MAZEL, Primary Examiner A. M. TIGHE, Assistant Examiner US. Cl. X.R. 7l92 PO-IObU (5,69) UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,503,978 Dated March 3;; 1970 Inventor) Adolf Zeidler et a1 It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

"Eolumn 1, line 32, "alkyl-" should read --a1kenyl- Column 2, line 7, "alkylene" 11 46 "d1 h d should read --a.lkeny1ene n8 0x0 3; r0-

should read dioxodecahydro- Column 4, in the table, 8th entry, second column, "-CO-i3H -CH=CH should read -CO-,CH-CH -CH=CH CH2 -CO-0C2H5 CH2 CO-0C2H5 SIGNED ANu SEALED JUL 211970 (SEAL) .Attest:

Edward M. Fletcher, Jr. L M E- OHUYLER. JR- Anesfing officer Commissioner of Patents 

